The problem is that you can easily read a concise article, nod your head, understand it, and then entirely forget it.
With a book, you get the main ideas presented multiple times, applied, examined, refined, put in context, etc. Now, you’ll also forget all that apparently extraneous stuff, but at least you’ll remember the main ideas.
I find myself wavering back and forth. Great fiction? Give me a big cinderblock of a book please. Full of world building and chapters dedicated to a single thread of thought going through a character's mind. Even to the point of sometimes when reading short fiction novels getting anxious towards the end, just knowing the ride is almost over.
Non-fiction/fact-based/instructional books I flip-flop hard between enjoying a brief enchiridion on leadership and management styles one moment while cradling a tome of a physics text book the next.
